JUNEAU, Alaska - Mushers and dog sled teams from around the world embark on the first leg of Alaska's grueling Iditarod Trail Sled Dog Race on Sunday, starting a nearly 1,000-mile (1,609 km) journey through the state's unforgiving wilderness.
Now in its 44th year, the race commemorates a 1925 rescue mission that delivered diphtheria serum by sled-dog relay to the western coastal community of Nome on the Bering Sea.
This year's Iditarod features 85 mushers and teams each made up of 16 dogs. They will set off on staggered starts from the town of Willow, an hour's drive northwest of Anchorage, where a ceremonial start was staged on Saturday.
The winner is likely to cross the finish line eight to 10 days later.
The race, which covers 975 miles (1,569 km) this year, is the test of extreme endurance. It features desolate stretches of up to 85 miles between checkpoints and unpredictable wind gusts as the trail hits the Bering coast.
Last year temperatures along the route plunged to 60 degrees Fahrenheit below zero (-51 Celsius).
Still, veteran musher Jeff King, 60, would not have it any other way. He has won four Iditarods, posted 19 top 10 finishes and 14 top five conclusions.
"I've finished with pneumonia, I've finished with the flu, I sprained an ankle and a knee to the point of where I didn't think I could go on," he said.
"But I finished."
King last won the race in 2006. Since then, two-time defending champion Dallas Seavey has posted three victories in four years, including a record performance in 2014, when he clocked in at eight days, 13 hours, four minutes and 19 seconds.
"The challenge to the Iditarod," Seavey said, "is not only doing 1,000 miles across terrain that's ever changing. It's the adjustment of the weather at a time when we're always pushing to the limits."
Aliy Zirkle, 46, remains a perennial contender, having posted four straight top five finishes, including three runner-up finishes.
Each year, Zirkle says she looks forward to hitting that vast expanse en route to the Bering Sea coastline.
"When you get 500 miles from nowhere, you stop. You get off, look at your dogs and they are wagging their tails at you and you think I just made it from Anchorage to the Bering Sea - just me," she said.
The winner will take home a cash prize of US$50,400 (S$69,000) and a new pickup truck. Other top finishers will share in a total cash purse of US$750,000.
Each team starts with 16 dogs, ranging from 3 to 8 years old, and is required to take a 24-hour rest, plus two separate eight-hour stops during the race.